Protective tube

ABSTRACT

The protection tube comprises a plurality of threads braided together or interwoven, and is characterised in that at least part of said threads comprises hot melt material. At least part of said threads is impregnated in said hot melt material or is made of hot melt material. 
     It allows the protection tube to be joined, totally or partially, to the element to be protected without requiring the use of any additional element.

The present invention relates to a protection tube, in particular forprotecting cables, which is secured at one end, at both ends or acrossthe entire length of the element to be protected.

BACKGROUND OF THE INVENTION

In the state of the art the use of protection tubes over elongatedelements, for example car cables, is known.

These protection tubes are made of a number of threads braided orknitted together, in such a way that they provide appropriate mechanicaland thermal protection.

One problem with the installation of these protection tubes is that theycan move in respect of the elongated element it protects over the courseof time.

One solution for this problem is described, for example, in patentEP-A-0 784 181. This patent describes a braided sheath sleeve whichincludes a certain quantity of adhesive between the filaments of oneexpanded end of the sheath and which is surrounded by a joint made ofhot shrink plastic material.

To secure the expanded end to the element to be protected a shapingmandrel must be placed and heat applied to said end in such a way thatthe adhesive melts and the joint is secured.

This sheath presents the disadvantage of requiring an additional elementaside from the sheath itself, the joint, to allow it to be secured tothe element to be protected, which represents an additional cost.

Therefore, there is an evident need for a protection tube that can besecured to the element to be protected in a faster and simpler manner,without needing to incorporate elements that do not form part of theprotection tube itself.

DESCRIPTION OF THE INVENTION

With the protection tube of the invention the aforesaid disadvantagesare resolved, presenting further advantages which are described below.

The protection tube of the present invention comprises a plurality ofthreads braided together or interwoven, and is characterised in that atleast part of said threads comprises a heat shrink material, in otherwords, there are the following options:

-   -   for all or some of the threads to be coated or impregnated in a        heat shrink material;    -   for some of the threads to be fully made of a heat shrink        material, which can also be impregnated in said material.

Thanks to this characteristic, to join the protection tube, totally orpartially, to the element to be protected it is not necessary to use anyadditional element.

According to a first embodiment, at least part of said threads isimpregnated with said hot melt material. Preferably, all threads areimpregnated with said hot melt material. In such case, said hot meltmaterial is preferably a hot melt resin or adhesive, or any suitablematerial. For example, said hot melt resin or adhesive may be apolyurethane-based adhesive.

According to an alternative embodiment, at least part of said threads ismade of a hot melt material. In this case, said hot melt material issynthetic rubber, or polyethylene, polypropylene, polyamide orpolyester, with a low melt point.

DESCRIPTION OF PREFERRED EMBODIMENTS

Below is a description of preferred embodiments of the protection tubeof the present invention by way of a non-limiting example.

According to a first embodiment, the protection tube of the presentinvention is a braided thread tube manufactured according to thefollowing parameters:

-   -   Number of spools: 32;    -   Threads per spool: 2;    -   Density: 25 stitches in 3 cm;    -   Type of thread: PET monofilament 0.22 mm black;    -   Type of resin for finishing: Heat activated adhesive with a        polyurethane base and in aqueous medium (40% solids content),        traded under the name Morchem 5152 HR;    -   Finishing process: by immersion;    -   Application model: on a polyamide gasoline tube with an 8 mm        diameter, the impregnated cover was applied and dried in a stove        during 30 seconds at 150° C.;    -   Conclusion: the tube is secured to the gasoline tube.

According to a second embodiment, the protection tube of the presentinvention can be carried out with a braiding machine in the followingway:

-   -   1) 3 spindle heads of PET polyester of 0.22 mm and 1 spindle        head of hot melt thread of 0.18 mm; and/or    -   2) 3 spindle heads of PET polyester of 0.22 mm.

All bobbins may be according to option 1) or may be 25% according tooption 1) and the remaining 75% according to option 2), and anycombination thereof.

The material of the protection tube may be polyester or any otherplastic material with polyamide.

It must be stated that the protection tube of the present invention canbe manufactured on circular gathering machines, circular warpingmachines, on braiding machines and on looms, using braiding, warpknitting, stitch gathering or fabric weaving techniques.

Also, the materials of the threads may be any plastic fibre, for examplepolyamide or polyester.

The method used for heating and shrinking the tube can be anyconventional method, for example, by means of hot air, infrared beamradiation, heat radiation, etc.

It must also be pointed out that the joint between the protection tubeof the present invention and the element to be protected can be at oneof its ends, at both ends, or across the entire length of the protectiontube.

Despite the fact that reference has been made to a specific embodimentof the invention, it is obvious for the person skilled in the art thatthe described protection tube can be subject to numerous variations andmodifications, and that all the details mentioned can be replaced byother technical equivalents, without departing from the scope of theprotection defined by the attached claims.

1. A protection tube comprising: a plurality of braided or interwoventhreads; and wherein at least part of said threads comprise a hot meltmaterial.
 2. The protection tube according to claim 1, wherein at leastpart of said threads is impregnated in said hot melt material.
 3. Theprotection tube according to claim 1, wherein at least part of saidthreads is made of said hot melt material.
 4. The protection tubeaccording to claim 1, wherein said hot melt material is a hot meltresin.
 5. The protection tube according to claim 1, wherein said hotmelt material is synthetic rubber, or polyethylene, polypropylene,polyamide or polyester, with a low melt point.
 6. The protection tubeaccording to claim 2, wherein all of the threads are impregnated in saidhot melt material.
 7. The protection tube according to claim 4, whereinsaid hot melt resin is a polyurethane-based adhesive.